Time to replace chainplates?

[indimini]

As part of my winter maintenance, I pulled off the starboard chainplates and noticed what I would describe as a " wood grain" pattern on the stainless plates. The stainless is not smooth and there was some brownish discoloration in the grain pattern on the plates.

Additionally, the aluminum backing plates show some distortion to the bolt holes.

The boat is new to us, but is 30 years old. I'm thinking I should at a minimum replace the aluminum backing plates, but I'm not sure if the pattern I see in the stainless is cause for concern. Age alone has me thinking it is prudent to replace these before next season but perhaps I am being overly cautious? Any feedback/info would be greatly appreciated.

The hole pattern on the plates (they are 14 1/4" long, x 2" wide and 1/4" thick) will require custom fabrication. Any recommendations on reliable sources would also be appreciated.

(I will try to post a pic if that would help.)

 

[Delezynski]

Indimini,

You might be interested in seeing our short Youtube video when we replaced our chain plates. It's at; http://youtu.be/z3MeKoKC5-0

It was a lot of work, but more than worth the effort!

Greg

 

[woodster]

As part of my winter maintenance, I pulled off the starboard chainplates and noticed what I would describe as a " wood grain" pattern on the stainless plates. The stainless is not smooth and there was some brownish discoloration in the grain pattern on the plates.

Additionally, the aluminum backing plates show some distortion to the bolt holes.

The boat is new to us, but is 30 years old. I'm thinking I should at a minimum replace the aluminum backing plates, but I'm not sure if the pattern I see in the stainless is cause for concern. Age alone has me thinking it is prudent to replace these before next season but perhaps I am being overly cautious? Any feedback/info would be greatly appreciated.

The hole pattern on the plates (they are 14 1/4" long, x 2" wide and 1/4" thick) will require custom fabrication. Any recommendations on reliable sources would also be appreciated.

(I will try to post a pic if that would help.)

that grain came from the factory that way it is called a brushed finish ..if you have no pits or penetrations in the plate material they will more than likely be fine ...but make sure you check the bolt holes for elongation as in out of round...especially the hole that the shroud pin goes through as for the brownish color .....take some lacquer thinner and clean it and see if it dissolves..if it does then it is more than likely teak oil stain from maintenance over the years ...if you feel the need to have new ones made i think a user named Recess knows a place in Valdosta Ga that can make them at a reasonable price hope this helps

 

[FastOlson]

It's been a lot of years, so...

At that age, if there is ANY doubt, replace them.
SS if you want them reproduced, and Titanium for a few $ more.

It's kinda like replacing shrouds after 15 or 20 years max. It's just good insurance. Once you get into the maintenance "twilight zone" of the years, the % chance of a failure just keeps rising. A rig failure is massively inconvenient at best and at worst someone gets injured or killed.

For more insight into the whole rig load and stress, and care-and-feeding, read the excellent rigging book by Brion Toss.
You have a nice boat that sails well; and preventative maintenance is just part of ownership.


fair winds,
Loren

 

[Delezynski]

At that age, if there is ANY doubt, replace them.
SS if you want them reproduced, and Titanium for a few $ more.

It's kinda like replacing shrouds after 15 or 20 years max. It's just good insurance. Once you get into the maintenance "twilight zone" of the years, the % chance of a failure just keeps rising. A rig failure is massively inconvenient at best and at worst someone gets injured or killed.

For more insight into the whole rig load and stress, and care-and-feeding, read the excellent rigging book by Brion Toss.
You have a nice boat that sails well; and preventative maintenance is just part of ownership.


fair winds,
Loren

VERY well said.

 

[gettinthere]

Flat bar stock as you describe should not be terribly expensive. Do not assume the port side is exactly the same! Send both off to the shop to be copied.

 

[indimini]

Thanks for the info everybody. There is no elongation in the holes on the stainless and they did clean up nicely, but I think for my own peace of mind, I will replace the plates to go with the new shrouds I am installing. 30 y.o. metal is bound to

It is good to know that the finish was by design and not a sign of deterioration.

 

[woodster]

on my 1979 i took all the chain plates out and cleaned them up and when stacked with holes lining up in the stack they were all the same exactly the stainless steel parts

the backing aluminum plates were two parts (two with two holes and two with three holes) on two of them and one part on four of them (four with five holes)

the quotes for making new ss only were from $200.00 and up ...i did replace all the 3/8" bolts and nuts and lock washers with new and polished the old ss plates to a mirror finish up to 1500 grit

 

[indimini]

Woodster, that's helpful information. I will polish up the SS plates and replace the aluminum backing plates since those show elongation in the holes. I found a source for the SS bar for under $100 for all six plates, but would still need to drill them out and round the edges - not sure if I can do that myself of farm out that work.

 

[Chief RA]

Any good metal shop or probably a college can test those plates for you. Way cheaper than replacing what is probably still good stock. Chief

 

[woodster]

you will be better off have a local machine shop make them ...that way if they get them wrong on the hole pattern you have a fall back and you wont go through the stress of making them with a drill press and burning up a bunch of drill bits ...they will use a milling machine and end mills to do the work and also coolant to keep from work hardening the stainless and save there mills if you had a 100 of then they would write a program for there water laser and make them that way ...you may find a small machine shop that can do water laser work in your area but most larger shops will have a minimum and it may be a little over the top cost wise shop around if you have them made for replacement ...what you do not want to do is have to ream out the wooden holes in your chain plate knees on the hull so an exact fit is important

while you have them out check you wooden knees for water damage and rot after all that is the weakest link in the chain if you have rot it may only be on one part and you can replace one layer of plywood in most cases and use the existing holes to re drill the holes back after the epoxy has set up i had to do this on two of mine plus replace the main bulkhead on the head wall

 

[indimini]

I definitely have rot at the top of the plywood behind the main shroud plates. I still need to determine how extensive the rot is.

 

[woodster]

while you have them out you may want to core out around the deck penetrations and fill with thickened epoxy to keep the water out of the deck core going forward...cut some plexi glass the size of your chain plates and wrap it with about 8 wraps of shrink wrap to create a mold of the hole and bolt them in place then fill the voids around where you cored out the deck and when it has set up to a solid remove the plexi or use 1/4 inch ply wood and when set drill out the plywood and clean up the hole ........

 

[indimini]

Great idea - I was planning on removing the rotten core and injecting epoxy, but love the idea of filling with epoxy around the entire chainplate. That will definitely help address any future water intrusion.